Musical box construction



April 7, 1959 w. o. GORR 2,880,639

MUSICAL BOX CONSTRUCTION 5 Sheets-Sheet 1 Filed July 12, 1954 INVENTOR.

WHLTER 0. wee BY ,7 A

A TTORNEY,

April 1959 w. c GORR 2,880,639

MUSICAL BOX CONSTRUCTION Filed July 12, 1954 3 Sheets-Sheet 2 INVENTOR.

United States Patent MUSICAL BOX CONSTRUCTION Walter O. Gorr, Glendale, Califi, assignor to Knickerbocker Plastic Co., Inc., North Hollywood, Calif., a corporation of California Application July 12, 1954, Serial No. 442,580

12 Claims. (Cl. 84-95) This invention relates to a musical toy, e.g., in the form of a music box, and more particularly concerns a novel combination of musical comb and clamping plate for use in a music box.

In musical toys or music boxes of the foregoing type, the construction generally includes a musical comb, the teeth or tines of which are sequentially arranged and adapted to be successively plucked throughout the length of the row in which they are arranged to produce a chosen melody. Music box instruments of this nature usually comprise a means for selectively plucking the free ends of the teeth to produce a tune. Such means may, for example, include a cylinder with projections punched up from the surface thereof, and rotated by means of a driving mechanism to bring the projections on the cylinder into striking contact with the free ends of the respective teeth of the comb at selected intervals, causing the teeth to vibrate and produce the desired tones. Like the notes of a diatonic scale, the reeds or teeth of the comb are struck at various predetermined times to produce the desired melody.

Despite the care exercised in the design and fabrication of such musical combs, it is often difficult to obtain the proper tone and volume of tone desired for the various teeth, and once the comb is cut or stamped, the tones produced by the various teeth are essentially fixed. This is due to the fact that in the prior art combs substantially only the teeth themselves vibrate when they are plucked and the base or block of the comb to which the teeth are attached, being fixed to the music box frame, is substantially prevented from vibrating and hence is unable to cooperate with the respective teeth of the comb to produce the desired quality and volume of tone. Moreover, when the comb is stamped in one piece, since the teeth are generally attached to the supporting member along an edge thereof disposed at an angle to the teeth, one side edge of a tooth is somewhat longer than the other side edge, and hence diflerent portions of each tooth tend to vibrate at different frequencies, impairing the quality of tone.

It is an object of the invention to provide musical combs, the teeth of which produce improved tone and volume of tone.

Another object is to afford a simple musical comb structure having sharp tones.

Still another object is the provision of a musical comb structure wherein the frequency of the teeth is increased to obtain sharp tones, and wherein such increase in frequency is adjustable.

The foregoing objects are accomplished according to the invention by positioning one or more clamping plates over the surface of the base or block of the comb, an edge of each of the clamping plates being positioned in a. certain relationship to the fixed ends of the comb teeth or to the ends of the spaces between the comb teeth and adjacent the fixed ends thereof. In the instant invention, one edge of the clamping plates has a configuration in the form of stepped treads located adjacent the fixed 2,880,639 Patented Apr. 7, 1959 ends of the comb teeth. The treads each extend across a portion of the comb block and terminate at a point located intermediate the teeth. In one embodiment, the edge of the tread extends transversely across the teeth in a direction normal thereto and terminates in a space between the teeth, and in another embodiment such edge terminates at a point on the block or supporting member of the comb, which is located in alignment with a space or slot between the teeth, i.e., directly above such space or slot. According to the invention structure the side edges of each tooth can be made elfifectively equal, and all portions of each tooth will therefore vibrate at substantially the same frequency, resulting in a purer tone.

Further, according to another feature of the invention, the edge of the clamping plate which is located adjacent the fixed ends of the teeth, is displaced a short distance along the comb block from the fixed ends of such teeth and the ends of the spaces between the teeth, to permit a portion of the comb block between the fixed ends of the teeth and said plate edge to be left uncovered by the plate. This permits such uncovered portion of the block to vibrate along with the teeth. In eifect, the teeth are thus made stiffer and vibrate at a higher frequency than they do when the clamping plate completely covers the comb block and extends thereon to the fixed ends of the teeth. I have found that the combination of the comb and the clamping plate or plates in the manner described above causes the comb to produce sharper tones and the volume of such tones is also increased without affecting the quality thezeof. Without being bound as to any theory for these improved resuits obtained by my structure, I believe that to at least some degree the specific design and positioning of the clamping plate or plates function to produce overtones which improve the tonal quality of the teeth when placed in vibration.

The invention will be more clearly understood from the description below of a preferred embodiment taken in connection with the accompanying drawings, wherein- Fig. l is a plan view of one embodiment of the comb and clamping plate structure of the invention;

Fig. la is a fragmentary section taken on line 1a1a of Fig. l;

Fig. lb is a fragmentary section taken on line 1b1b of Fig. l;

Fig. 2 is a view similar to Fig.1, showing another em} bodiment of the invention;

Fig. 2a is a section taken on line 2a-2a of Fig. 2;

Fig. 2b is a section taken on line 2b2b of Fig 2; v f

Fig. 3 is a view similar to Fig. 1, showing another embodiment of the invention;

Fig. 3a is a section taken on line 3a3a of Fig. 3;

Fig. 4 is a plan view of my device assembled to form a musical box with the top of the case broken away; 7

Fig. 5 is a section taken on line 5.5 of Fig. 4, and shown partly in full lines for clarity; and

Fig. 6 is a section taken on line 6-6 of Fig. 4.

Referring particularly to Fig. 1 of the drawings, nu meral 10 represents a musical comb comprising a series of spaced parallel reeds or teeth 12 each fastened at one end 13 to a supporting member or comb block 14. Block 14 is positioned at an acute angle to the teeth, and a line joining the lower opposite ends of the comb block forms an acute angle with the comb teeth. The elongated teeth are varying lengths to produce the desired tones, the free ends 16 of the teeth being in alignment with each other. In the embodiment of Fig. 1, several pairs of teeth are shown, the teeth of the respective pairs being substantially of equal overall length. It is understood, of course, that the length and location of the various teeth of the comb may be varied, and some teeth may have the 3 same length as others. The comb may be formed by punching out the teeth from a single strip of sheet steel or other metal such as aluminum or Phosphor bronze, and the comb including the teeth thereof is of uniform thickness throughout.

A pair of clamping plates 18 are positioned in alignment with each other and in contact with the opposite sides of the block 14 of the comb. The side edges 17 and 17' and the top edge 19 of each of the plates have substantially the same contour as the corresponding side and top edges of the comb block 14, so that the plates substantially overlie the entire surface of the supporting member or block 14. Apertures 20 are provided in the plates 18 to receive screws 21 or other similar fasteners to secure the plates on the comb and to fasten this assembly to the frame of the music box mechanism as described more fully hereinafter.

According to my invention it will be seen that the lower edge 22 of each of plates 18 has a configuration in the form of progressive stepped treads or serrations 23. each of the steps extending across at least one of the teeth 12 in a direction normal thereto, and along a line passing through the end of a spacing 24 adjacent such tooth or teeth. These treads terminate approximately midway across the spaces 24 between the teeth 12. Thus, for example. the tread 23 between points A and B extends from point A at the inner end of a space 24 across tooth 12a in a direction normal thereto, and terminating in a point B about midway across the slot 24 on the other side of tooth 12a. Tread 23 defined by points A and B has a side edge which extends from point B upwardly along such slot 24 parallel to teeth 12 for a short distance to point C l cated at the upper end of th s slot. The ad- I jacent tread 23 commences at point C and has a horizontal edge traversing two teeth 12!; and 120, such edge passing through the end of the s ace 24 between these teeth. and terminating at a point D. preferably about midway across another space 24. In like manner, successive stepped treads are formed between points E and F, G and H. .l and K, L and M, and N and O. In this manner, the effective length of the side edges of each of the teeth 12 are made substantially equal; for example, in the case of tooth 12a, side edge 12' is substantially equal to side edge 12". and each of these teeth vibrate uniformly to produce the desired proper tone.

In'the embodiment shown in Fig. 2, the plates 26, having treads 27, are positioned on a comb 28 having teeth 30, so that each of the treads 27 of the plates extends across at least one of the teeth 30 in substantially the same manner as in Fig. l, each tread terminating along its lower edge in a space 32 between the teeth. However, in the instant embodiment, the plates are set back from the inner ends 34 of the spaces 32 so as to leave a portion 36 of the base metal of the comb block 38 between the adiacent tread 27 and the adjacent ends 34 of the spaces 32. uncovered by plates 26. Thus, the tread 27 between points P and Q extends from a point P on block 38 above the inner end of the ad acent space or slot 32 across the comb block 38 and teeth 30a and 30b to a point Q midway between another space or slot 32 just below the end 34 of such slot. From point Q, the side edge of the tread extends upwardly parallel to the teeth to a point R on the comb block 38 above the end 34 of the slot 32 directly below. From point R, another tread 27 extends horizontally along the block 38 and above the slot 32 between teeth 30c and 30d to point S about midway of another slot 32. In like manner, additional treads 27 are positioned so as to permit additional portions 36 of base metal to be exposed.

According to the embodiment of Fig. 2, it is seen that the portions 36 of block 38 left uncovered by plates 26 form additions to the fixed ends of the teeth 30, which stiffen the teeth so as to impart a higher frequency to the teeth than in the case where the plates 26entirely 4 cover the comb block 38. Moreover, vibration of pottions 36 of the comb block with the teeth produces greater volume of tone.

It is seen that each of the uncovered portions 36 of metal is in the form of a rectangle. Thus, for example, the rectangular portion 36 formed above teeth 30a and 30b is bounded by the portion PT of the edge PQ of the adjacent tread 27, and the horizontal line P'T extending from the tread 27 on the left of tooth 30a to the right edge of tooth 30b; and the rectangular portion 36 formed above the single tooth 30a is bounded by the portion VW of the edge VX of the adjacent tread 27, and the horizontal line VW' extending from the tread on the left of tooth 30e to the right edge of tooth 302. It is noted that when a tread 27 crosses above two teeth of substantially the same length, e.g., the tread having the edge PQ crossing above teeth 30a and 3017, this produces a double note. Further, it is seen that the rectangular portions of uncovered metal 36 can vary in area. Thus, for example, uncovered portion 36 above teeth 30a and 30b is greater in area than that above teeth 30c and 30d. The reason for this is to obtain the correct pitch and timbre of tone, which are dependent on the production of the proper harmonics and overtones. It will be understood by those skilled in the art that a certain amount of trial and error is required with respect to the exact relationship or distance between the edges of the treads 27 and the inner ends of the adjacent spaces 32 between the comb teeth, to obtain the proper area for the various uncovered portions 36 in order to realize the best results.

The embodiment of Fig. 3 essentially combines the features of the combs of Figs. 1 and 2. Referring to Fig. 3, the comb 42 has a block 44 disposed at an acute angle to the parallel teeth 46 which are integrally connected to the block 44, the teeth being of progressively increasing length across the comb. An extension or ear 48 is formed along the lower edge of comb block 44, adjacent the fixed end 50 of each of the teeth. Each of these extensions projects into a space or slot 52 between the teeth, and has one edge 54 extending normal to the adjacent tooth, and substantially in alignment With the end 56 of the space 52 on the opposite side of such adjacent tooth. Ear 48 has a second edge 58 extending from the end of edge 54, upwardly parallel to the teeth 46, until it joins the curved inner end 56 of another space 52 be tween the teeth. Thus, a series of extensions 48 are formed along the lower edge of block 44 adjacent the fixed ends of each of the teeth 46. It is seen from this construction that the efiective length of side edges 46' and 46" of each of the teeth 46 are of equal length, as brought about in the embodiment of Fig. 1, and hence each of the teeth vibrates uniformly.

Plates 59 positioned on both sides of block 44 of comb 42, have a plurality of stepped treads or serrations 60. The plates are positioned on the block 44 so that the hori zontal edge 62 of each tread extends across a tooth 46 parallel to edges 54, and spaced a short distance above said edges. Each of edges 62 of plates 59 terminates at a point somewhat short of the vertical edge 58 of the adjacent ear or extension 48 on the block 44, and above a space or slot 52 between the teeth. Each tread has a vertical edge 64 which extends parallel to vertical edge 58, upwardly to the horizontal edge 62 of the next tread 60. It is accordingly seen that a portion 65 of block 44 is left uncovered by plates 59 between each of the edges 62 of the treads on such plates, and the adjacent edges 54 and the inner ends of the adjacent spaces 52 between the teeth; also a portion 66 of block 44 is left uncovered by plates 59 between a vertical edge 64 of the plates 59 and the adjacent vertical edge 58 of block 44. Thus, a zigzag or stepped strip of metal 67 of block 44 extending from one end of the block to the other along its lower edge is left uncovered by each of the plates 59. This strip of metal tends to stiffen the teeth 46, and to thus confer a higher frequency of vibration on the teeth 46,

as in Fig. 2, than would be the case if such strip of metal were completely covered by the plates 59. This pro duces sharper tones and also greater volume of tone because the above strip of uncovered base metal of the block 44 is set into vibration when the teeth vibrate, as in the embodiment of Fig. 2.

.It is thus seen that the structure of Fig. 3 combines improvement in tone quality obtained according to the structure of Fig. 1, with sharpness and increased volume of tone obtained according to the embodiment of Fig. 2. It will be understood, by those skilled in the art that the position of the stepped edges 62 of clamping plates 59, with respect to the zigzag edge of the comb block 44 to which the teeth 4-6 are joined, can be varied by adjustment of plates 59 to obtain the correct pitch and timbre of tone, as well as to change sharpness of tone and amplitude thereof (loudness).

It should be understood also that the design and number of teeth in the combs of Figs. 1, 2 and 3 may be varied as desired, and that the stepped treads of the clamping plates of these embodiments may be varied accordingly. Thus, for example, two teeth may be of the same length to form a double note, and each of the treads may be of length such as to traverse one, two or more adjacent teeth. Further, particularly in the embodiments of Figs. 1 and 2, it is not necessary that the treads commence and terminate midway across the spaces between the teeth, so long as these terminal points are located somewhere within these spaces.

The above described comb and plate assemblies are assembled in a music box by positioning the assembly at one end of a frame 68, see Fig. 4, and fastening the comb, e.g., comb 10, and plates 18 to the frame by means of the screws 21. The frame 68 is positioned within a housing or case 70 by means of screws or other fasteners 72 passing through brackets 74 located along the sides of the frame, and into the base 76 of the housing. It is seen from Fig. 6 that the lower plate 18 separates the comb from the end 78 of the frame to which it is attached, and that the comb and its teeth 12 are out of contact with the frame so that the teeth are free to vibrate when plucked in the manner described below. A substantially rectangular space 80 is formed in the frame by the arms 82 and the cross member 84 thereof, and by the lower end of the comb defined by the free ends 16 of the comb teeth 12. In this space is positioned a cylinder 86 mounted for rotation on an axle 87 journaled in end members or brackets 88 and 89 on arms 82. The cylinder 86 is generally formed of a sheet metal strip which is rolled into the form of a cylinder, the ends of which are positioned by suitable means in caps 90 carrying the axle 87. While in flat sheet form, projections in the form of flaps or tongues 91 are punched up from the surface of the sheet, so that when the sheet is rolled into the form of a cylinder and positioned in frame 68 between end members 88 and 89, these projections are in alignment with the teeth 12 of the comb and are so spaced from each other as to give the desired tones when the drum or cylinder is rotated to bring these projections into contact with thee free ends 16 of the teeth. The cylinder 86 is positioned in the frame so that the outer surface of the cylinder is spaced substantially parallel to a line joining the free ends of teeth 12, such surface being disposed a short distance from the free ends 16 of the teeth so that the projections 91 on the cylinder will pluck the free ends of the teeth when the cylinder is rotated. It is seen in Fig. 6 that cylinder 86 is positioned in the frame so that comb 10 is in a horizontal plane in alignment with a diameter of the cylinder. A pinion 92 for driving cylinder 86 is fixedly connected axially to axle 87 adjacent one end of the cylinder and the adjacent frame bracket 89. Member 93 for op .erating the pinion is in the form of a rod 94 which ex:

tends through an aperture 95 in the case 70, the rod having a crank 96 and a handle 97 connected at right angles to the outer end of the crank. The outer end 94 of rod 94, including crank 96 and the handle, is located outside of case 70. At the inner end of the rod a worm gear 98 is provided by winding a wire in the form of a spiral about a portion of the rod. The rod 95 is positioned on a bracket 99 freely mounted on axle 87, so that worm 98 is in meshing engagement with the teeth of pinion 92 for driving same and the cylinder 86, on rotation of crank 96 through manual manipulation of handle 97. Such operation of the handle and crank brings the projections 91 on the cylinder 86 into successive contact with the ends of the various teeth 12 of the comb, to cause vibration thereof and produce the desired tones according to the invention. Rod 95, including the worm 98 carried thereby, is journaled for rotation within the aperture 95 of the case, and is fixed against longitudinal movement by bracket 99.

If desired, instead of employing a pair of base members or clamping plates, e.g., plates 18, for each comb, I may use only one of such plates, or more than two of these plates positioned against the block 14 of the comb, as described above, the plates being in alignment with each other and fastened to the comb in any desired manner.

While I have described a particular embodiment of my invention for the purpose of illustration, it should be understood that various modifications and adaptations thereof may be made within the spirit of the invention as set forth in the appended claims.

I claim:

1. Ina musical instrument, a plurality of spaced parallel elongated pluckable teeth, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the otherend of each of said teeth being free to vibrate, a clamping plate positioned on said supporting member, said plate being substantially free from contact with said teeth, one edge of said plate having a configuration in the form of stepped treads located adjacent the fixed ends of said teeth, said treads each extending across a portion of said supporting member, said treads terminating at a point located intermediate said teeth.

2. In a musical instrument, a plurality of spaced parallel elongated pluckable teeth, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other end of each of said teeth being free to vibrate, a clamping plate positioned on said supporting member, said plate being substantially free from contact with said teeth, one edge of said plate having a configuration in the form of stepped treads, said treads extending across a portion of said supporting member in a direction normal to said teeth, each of said treads terminating between said teeth.

3. A musical. instrument which comprises a plurality of spaced parallel elongated pluckable teeth of varying length, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other end of each of said teeth being free to vibrate, a clamping plate positioned on said supporting member, one edge of said plate being in the form of a series of stepped treads, each of said treads being substantially free from contact with said teeth and extending across a portion of said supporting member transversely of at least one of said teeth along a line passing through the inner end of a space adjacent the fixed end of said at least one of said teeth, said treads terminating in a space between said teeth.

4. A musical instrument which comprises a plurality of spaced parallel elongated pluckable teeth of varying length, a frame, a block for supporting said teeth, said block being positioned at an acute angle to said teeth, one end of each of said teeth being integrally fixed tosaid block, the other end of said teeth being aligned and free,

. having an extension adjacent to vibrate, a clamping plate positioned on said block, one

edge of said plate being in the form of a series of stepped treads, each of said treads being substantially free from contact with said teeth and extending across a portion of said supporting member transversely of at least one of said teeth in a direction normal thereto and along a line passing through the end of a space adjacent the fixed end of said at least one of said teeth, each of said treads terminating approximately midway across a space adjacent said at least one of said teeth, and extending in a direction parallel to said teeth to an adjacent tread, means for securing said block and said clamping plate in said frame, and means for selectively plucking the free ends of said teeth to produce a tune.

5. A musical instrument which comprises a frame, a musical comb, said comb including a plurality of spaced parallel elongated pluckable teeth of varying lengths, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other ends of said teeth being free to vibrate, a clamping plate positioned on said supporting member, one edge 'of said plate being in the form of a series of stepped treads, each of said treads extending across a portion of said supporting member substantially free from contact with said teeth and along a line spaced from the inner ends of the spaces adjacent the fixed ends of said teeth, said treads terminating at a point between said teeth.

6. A musical instrument which comprises a frame, a musical comb, said comb including a plurality of spaced parallel elongated pluckable teeth of varying lengths, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other ends of said teeth being free to vibrate, a clamping plate positioned on said supporting member, one edge of said plate being in the form of a series of stepped treads, each of said treads extending across a portion of said supporting member substantially free from contact with said teeth and along a line spaced from the inner ends of the elongated spaces adjacent the fixed ends of said teeth, said treads terminating in longitudinal alignment with a space between said teeth, and leaving a section of the surface of said supporting member uncovered by said clamping plate, said section having a zigzag shape and located between said treads and a line parallel thereto and passing through the inner ends of said spaces.

7. A musical instrument which comprises a plurality of spaced parallel elongated pluckable teeth of varying length, a frame, a block for supporting said teeth, said block being positioned at an acute angle to said teeth, one end of each of said teeth being integrally fixed to said block, the other end of each of said teeth being aligned and free to vibrate, a clamping plate positioned on said block, one edge of said plate being in the form of a series of stepped treads, each of said treads extending along a portion of said block substantially free from contact with said teeth and along a line spaced a short distance from the free ends of the spaces adjacent said teeth, said treads terminating approximately midway between said teeth, and extending in a direction parallel to said teeth to an adjacent tread, means for securing said block in said frame, and means for selectively plucking the free ends of said teeth to produce a tune.

8. A musical instrument which comprises a frame, a musical comb, said comb including a plurality of spaced parallel elongated pluckable teeth of varying lengths, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other ends of said teeth being free to vibrate, each of said teeth the fixed end thereof, said extension extending into the space adjacent each said tooth and having one edge located normal to said tooth and a second adjacent edge located parallel thereto, a clamping plate positioned on said supporting member, one edge of said plate being in the form of a series of stepped '8 treads, each of said treads extending across a portion of said supporting member out of contact with said teeth and along a line spaced from the inner ends of the spaces adjacent the fixed ends of said teeth, said treads each terminating at a point on said supporting member spaced from said second edge of said extension.

9, A musical instrument which comprises a frame, a musical comb, said comb including a plurality of spaced parallel elongated pluckable teeth of varying lengths, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other ends of said teeth being free to vibrate, each of said teeth having an extension adjacent the fixed end thereof, said extension extending into the space adjacent each said tooth and having one edge located normal to said tooth and a second adjacent edge located parallel thereto, a clamping plate positioned on said supporting member, one edge of said plate being in the form of a series of stepped treads, each of said treads extending across a portion of said supporting member out of contact with said teeth and along a line spaced from the inner ends of the spaces adjacent the fixed ends of said teeth, said treads each terminating at a point on said supporting members spaced from said second edge of said extension and located between said teeth, and leaving a zigzag section of the surface of said supporting member uncovered by said clamping plate, said zigzag section being located between said treads and the edge of said supporting member to which said teeth are fixed.

10. A musical instrument which comprises a plurality of spaced parallel elongated pluckable teeth of varying length, a frame, a block for supporting said teeth, said block being positioned at an acute angle to said teeth, one end of each of said teeth being integrally fixed to said block, the other end of each of said teeth being aligned and free to vibrate, said block having a portion extending from the fixed end of each of said teeth into the space adjacent each said tooth, said portion having one edge positioned normal to said tooth and a second adjacent edge positioned parallel thereto, a clamping plate positioned on said block, one edge of said plate being in the form of a series of stepped treads, each of said treads extending along a portion of said block out of contact with said teeth and along a line spaced a short distance from the inner ends of the spaces adjacent the fixed ends of said teeth, said treads each terminating at a point on said block spaced a short distance from said second edge of said portion and located between said teeth, each of said treads extending from said point in a direction parallel to said teeth to an adjacent tread, means for securing said block in said frame, and means for selectively plucking the free ends of said teeth to produce a tune.

11. In a musical instrument, a plurality of spaced parallel elongated pluckable teeth, a supporting member for said teeth, one end of each of said teeth being fixed to said supporting member, the other end of each of said teeth being free to vibrate, a base member on said supporting member, said base member being substantially free from contact with said teeth, one edge of said base member having a configuration in the form of stepped treads located adjacent the fixed ends of said teeth, said treads each extending across a portion of said supporting member, said treads terminating at a point located intermediate said teeth.

12. A musical instrument which comprises a frame, a musical comb mounted in said frame and including a plurality of spaced elongated pluckable teeth and a base member, one end of each of said teeth being fixed to said base member, the other ends of said teeth being disposed in a substantially straight line and being free to vibrate, the edge of said base formed by the line joining the ends of the spaces between said teeth defining an irregular essentially ascending line other than a straight line, a clamping plate connected to a surface of said comb base, one edge of said plate forming an irregular essen 9 tially ascending line other than a straight line substantially following said edge of said base, said one edge of said plate having a configuration in the form of a plurality of ascending treads each extending across at least one of said teeth, and a block connected to said frame, said comb base and plate being connected to said block.

10 Howe Nov. 8, 1949 Handler Apr. 4, 1950 Blair Apr. 18, 1950 Duncan Apr. 18, 1950 Duncan Mar. 10, 1953 Bangs et al Feb. 21, 1956 FOREIGN PATENTS Switzerland Feb. 1, 1949 

